Karyopharm Therapeutics raised close to $50 million just a few months ago to continue developing its lead cancer drug. Now it’s turning to Wall Street to help with the effort. Karyopharm filed a Form S-1 with the SEC late Friday outlining plans to raise up to $80 million through an IPO, hoping to capitalize on the wide open window for life sciences offerings and help push its lead drug, now known as selinexor, into at least two—and potentially four—mid-stage clinical trials next year.